[2][3][4] Once considered part of the order Ulotrichales, molecular phylogenetics have shown that Geminella and related genera (such as Gloeotilopsis) form a well-supported clade within the class Trebouxiophyceae.

[5] Geminella is most often found in fresh water such as swamps, ponds, and lakes,[1] and is often associated with desmids.

[6] Geminella consists of uniseriate, unbranched filaments either free-floating or attached to a substrate.

The cells are generally separated and equidistant, or may be lying in pairs, and are surrounded by a thick mucilaginous sheath.

[6][1] Reproduction occurs by the fragmentation of filaments, or by the production of akinetes with thick brown cell walls.